In aerobic composting of refuse and night soil (Indore method), destruction of pathogenic organisms and parasite ova occurs primarily during which phase?
- A Thermophilic phase when the heap temperature rises to about 60 degrees C ✓
- B Initial mesophilic bacterial breakdown in the first week
- C Final cooling and maturation phase
- D Earthworm-mediated decomposition in the finished heap
Correct answer: A. Thermophilic phase when the heap temperature rises to about 60 degrees C
Explanation
As aerobic decomposition proceeds, heat generated inside the heap raises the temperature to around 60 degrees C or more, and this thermophilic phase lasting several days destroys pathogenic bacteria, viruses and helminth ova. This self-sterilizing heating is the key sanitary advantage of aerobic composting over simple dumping. Vermicomposting uses earthworms but operates at ambient temperatures and does not reliably kill ova. The initial mesophilic and final maturation phases occur at temperatures too low for pathogen kill.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.